Plate clamp



B. C. WHITE PLATE CLAMP Filed Dec. 9. 19.22 3 Sheets-Sheet 1 Oct. 28, 1924* 1,513,304

B. C. WHITE PLATE CLAMP Filed Dec. 9.` 1922 5 Sheets-Sheet 2 Oct. 28, 1924.

B. C. WHITE PLATE CLAMP Filed Dec. 9

` 1922 1 3 Sheets-Sheet 5 Patented et. 2S, 1924.

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BRUCE CLARK wennen, ou Nnw Yon-K, N. Y., nssrenoa To n. Hon AND oo or NEW Yoan, N. Y., e CORPORATION o-F New YORK.

PLATE CLAMP To all whom it may concern:

Be it known that I, BRUCE CLARK WHITE, a citizen vof the United States, residing at New York, county of N ew York, and State of New York, have invented certain new and useful Improvements in Plate Clamps, fully described and vrepresented in the following specification and the accompanying drawings, forming apart of the same.

My invention relates to plate clamping mechanism for rotary printing presses and its object is to provide clamping mechanism for holding printing plates upon the plate cylinder which can be operated quickly and easily by a single operation and cannot become loose afterit is once tightened and will be suliic-iently yielding in its grip vupon the edges of the plates to insure the holdingl of the plates at several points even though the plates vary slightly in size or form.

Another object of my invention is to provide a wrench for operating the clamping mechanism so constructed that it can be applied or removed only at the extreme limits of the movement of the clamping device, when the clamps are either full open or properly locked upon the plates.

vA further object of my invention is to so arrange the mechanism that the wrench will be out of the way of the plate and operator when the clamps are open, but will be in his way when the plates are locked and until the wrench is removed.

Further objects of my invention are to provide for clamping or releasing the inner or middle plates when outer plates are absent, as is sometimes the case in cylinders arranged for 4 plates abreast, when printing the middle pages only.

It has been common practice heretofore to force the `clamps against the plates by screws, operated by a wrench or ratchet.

These devices are slow in action and have a fixed rate of movement of the clamps correessential or desirable in such a mechanism.

ln the accompanying 'drawings which illustrate my invention,-Fig. 1 is a plan view of a part of one plate cylinder, withmy plate clamping device attached thereto. Fig. 2 is a vertical section of same on line 1-1 of Fig. 3. Fig. 3 is an end elevation. Fig. 4 is an enlarged detail section on line 2 2 of Fig. 5. Fig. 5 is a part plan and a part sectional view on line 3-3 of Fig. 4. y

Figs. 6 and 7 are detailed views of the end of the wrench. Figs. 8 and 9 are detailed views of the springs. Fig. 10 is a plan view of a modification of my'clamping device adapted to plates of a predetermined width. Fig. 11 is a vertical section of same on line 4 4 of Fig. 12. Fig. 12 is an end elevation of same.-

Referring to thedrawings, 10 indicates a plate cylinder of the usual form, provided with a shaft 11. The cylinder is provided with a plurality of slots 12, extending a suitable distance into the cylinder longitudinally thereof, in which areslidably mounted plate clamps 13 which are of the usual construction and are adapted to engage the outer bevelled edges of the printing plate 14 in a manner to retainV said plate upon said cylinder Vwhen the clamps are forced against it. l

At the outer ends of the slots 12 are sliding blocks 15 slidably mounted in said slots. Both the plate clamps 13 and the sliding blocks 15 are internally threaded toy engage threaded portions ofthe rods 16, one end of which has a right-hand thread and the other end a left-hand thread. A portion 17 of each of these rods is of square or hexagonal section whereby it may be turned by a. suitable wrench to adjust the distance between the plate clamp 13 and the corresponding sliding block 15 as desired.

Each sliding block 15 is provided with a projecting part 18 preferably made integral with the sliding: block and cylindrical form and preferably provided with an antifriction roller 19.

The rollers 19 lit freely in diagonal cam slots 2O formed yin the curved cam segment 21, which latter is fitted to rotate upon the hub 22 ofthe cylinder 10 through a short arc of angular movement. The cam segment 2l is limited in longitudinal movement between the shoulder 23 of the cylinder 10 and the collar 24, which latter is preferably made in halves for convenience in assem bling and is secured to the cylinder hub by screws 25.

Provision is made for a slight longitudinal movement of the cam segment 21, which movement is resisted by springs 26, preferably one being provided in line with each sliding block 15. Each spring is placed in a suitable pocket 27 in the collar 24. The said collar preferably extends into an annular recess 28 formed in the cam segment 21. By this arrangement the springs are enclosed and are retained in their pockets. rlhe springs are formed with the proper curvature to cause them each to bear at their middle point against thc cam sega/lent 2l and at each end against the collar 24 with such initial pressure as may be. desired for frictional resistance against the angular iuovementof the cam segment 2i. rlihe longitudinal movement of the said cam segment away from the plate i4 when the clamps are forced against the plate will cause the springs to straighten and react with such resistance as may be desired at the time of final pressure.

The cam slots 20 are preferably formed in a. diagonal direction, as shown at 29, which diagonal direction gradually changes into a curved path 30 of lessening angularity until at the end of the groove it is practically at right angles to the longitudinal axis of the cylinder 10.

The resultant longitudinal movement of the sliding blocks 15 toward the plate will be at first relatively fast as the cam segment is moved from its extreme right hand position tovvard the left., Fig. 1. A s the plate clamps 13 meet the plate 14 the sliding blocks move inward more sloWl-y and With increasing leverage and force until their inward movement ceases and the leverage is multiplied greatly. At the final position the springs 26 are stressed more or less according' to the inequalities in the plates. By adjusting the right and left hand screws 16 the. Whole or any part of the spring tension may be applied to the plate clamps as desired.

To operate the cam segment 21 through the required are of movement l preferably use a crank arm 31 Whose shaft 32 is rotably journalled in a hole in the end of the cylinder 10. The said crank is provided With a crank pin 33 preferably mounted With an anti-friction roller The hub of the crank arm is preferably square at 35 and has projecting flanges formed upon it at 36. fin open-end Wrench 537 is fitted to slide freely onto the squared portion of the said crank arm between the flanges 8G and the end Wall of the cylinder 10. rllhe wrench 37 is provided with projecting lugs 38, preferably on both sides. Grooves 39 formed in the end Wall of the cylinder l() extend from the periphery of the said cylinder radially toward the center of shaft 32 of the crank arm 81. An annular recess or counterbore 40 provides clearance for the lugs 38 when the Wrench is moved through its arc, which movement is limited by stop pins 41 in each direction. These parts are so arranged that the Wrench can be slipped onto the square of the crank only When the center line of the crank arm 31 and one of the grooves 39 coincide and obviously the Wrench 37 can be removed only in these positions. Any angular movement of the Wrench when it is on the said crank arm, from either of its extreme positions, locks the wrench and prevents its removal until it has completed its movement in either direction.

rl`he crank pin roller 34 is fitted to move freely in a groove or recess 42 extending across the inner face of the cam segment 2l. This groove is inclined from a. radial line suf ficiently to form a. right angle With the crank arm 31 when the latter is at the extreme limit of its movement to the left (see Fig. 4) corresponding With the position of the parts at the time of final pressure of the plate clamps 13 against the plate. ylhis arrangement results in the slowest move ment of the cam segment relative to the angular movement of the Wrench at the time of greatest pressure upon the plate 14 and consequently the greatest leverage of the Wrench at this time.

The leverage of the Wrench over the plate clamp is therefore a multiple of the two cam leverages, both of Which are practically infinite at the end of the pressure stroke. To provide for clearance for the crank arm 31 and Wrench 37 it is necessary tc cut recesses 43 in the cam segment 21.

The dotted line 44 indicates the position of the Wrench when the clamps are open. The Wrench 87 is then out of the Way of 'the operator. The dotted line 45 indicates the position of the Wrench 'when the plates are locked up. The Wrench in the latter position is in the ivay of vthe operator and he must remove it to get out from the operating space between the cylinders. rllhis arrangement assures the removal of the Wrench before starting the press. The Wrench may be left on in position 44 While changing plates.

Double clamps 46 are fitted to slide freely in the slots 12 of the cylinder 10 When tW'o plates are placed end to end along the cylinder each Way from the center. These clamps 46 are each provided with a spacer bar 47. il head 4&3 is screwed ont-o the said spacer bar and may be adjusted thereon as desired. lhe spacer bar 47 is fitted to slide freely in the bearing block 49.

l/Vhen the outer plate 14 is not used, the inner plate may' be clamped by adjusting the plate clamp 13 inward by the screw 16 until it contacts with the head 46 when its movement, through the cam movement of the sliding block 15, will cause the inner plate to be clamped by the double clamp 46. The purpose of the adjustable head 48 is to permit of an adjustment of the distance necessary to move the plate clamp 13 to effect the clamping of the inner plate, whatever the width of plates may be. Thus the minimum of adjustment isrequired for a change from full width oi.y web to half web or dinkey sheet, when the latter is run on middle pages. Likewise all or' the parts are available for a change from 8 to 7 columns, and either width may be run with equal economy of time in plate changing and lock-up.

Referring now to Figs. 10, 11 and 12 the device shown therein is of the same character and principle of operation as that already described except that the clamps 50 are operated directly by the cam segment 21 without the adjustable connections 16 and sliding blocks 15. This type of clamp is adapted to plates of a predetermined width in which but little, if any, adjustment of the clamps is required. A modified form of abutment collar 51 is shown, secured to the cylinder by bolts 52 screwed into the end wall of the cylinder. The collar is made preferably slightly yielding longitudinally by providing springs 53 between the heads of the bolts 52 and the collar 51. These springs are preferably of the dished washer type. They serve the same purpose as the springs 26 of the device iirst described.

The inner plate clamps 46 are forced against the inner plate 14 by the rods 54 which are screw threaded through the outer clamp 50, and extend through the inner clamps 46 and are provided each with a collar 55y and nuts 56. Then the outer plate 14 is absent a few turns of the screw 54 will bring their collars 55 against the inner clamps 46 in a manner to utilize the plate lock-up device for locking up the inner plates in the same manner as for the outer plates.

Vhen it is desired to open the clamps and release the printing plates, a movement of the cam segment ring 21 to the right moves the clamps 50 away from the outer plate 14 and at the same time pulls the clamps 46 away from the inner plate 14. The relative opening movements of the two sets of clamps 46 and 50 is such as to permit both inner and outer plates 14 to be removed clear of the clamps, and is effected by one movement of the operating wrench, which acts with suicient leverage and power to positively withdraw the two sets of plate clamps against their tendency to stick fast in their grooves.

It will be understood that the device shown is for a single lock-up device. lt will be duplicated upon the other half of the cylinder and a pair of lock-ups will be used ordinarily at each end of the cylinder. It is obvious, however, that without departing from my invention, a plate cylinder might bev used of such circumference as to carry more than two plates around its circumfer'ence or more or) less than :tour plates abreast. It is also obvious that the number of plate clamps along the margin of a plate is not limited to three, as shown, but may be more or less. Also that space, dimensions and other cir-cumstances may modify the details without changing the principle of the invention.

TVhat I claim as my invention and desire to secure by Letters Patent, is,-

1. The combination with a plate cylinder and plate clamps and blocks slidingly mounted thereon and movable longitudinally thereof; unyielding lengthwise adjustable connections between said plate clamps and said blocks; means tor moving said blocks longitudinally and a yielding resistance to said moving means independent of the clamp or block.

2. The combination with a longitudinally grooved plate cylinder and plate clamps and blocks both longitudinally movable in the grooves of said cylinder and unyielding adjustable connections between said plate clamps and blocks, of yielding elements on said cylinder, and clamp actuating means between said yielding elements and said movable block j '3. The combination of a plate cylinder, a printing plate thereon, longitudinal grooves in said cylinder, plate holding clamps longitudinally movable in said grooves, blocks likewise movable in said grooves, unyielding Vadjustable connections between said clamps `and blocks and means for moving said blocks, comprising a peripherally movable curved -segment having diagonal grooves adapted to engage said blocks, and means for actuating the said segment.

4. The combination of a longitudinally plate holding cylinder having plate clamps and blocks both longitudinally movable in the cylinder grooves, said clamps and blocks ybeing adjustably and unyieldinglyk connected, a diagonally gr'ooved peripherally movable segment i'or actuating the said blocks and plate clamps; a shoulder upon said cylinder and yielding elements between said shoulder and said segment to limit the longitudinal pressure thereon and means for actuating the segment.

5. The combination of a. plate holding cylinder having longitudinally movable diagonally grooved segment 'for moving the plate yclamps longitudinally and means for moving the segment comprising a slot across said segment, and a crank arm, the crank pin otl which engages said slot, and means for actuating said crank arm.

(3. rEhe combination ot a plate cylinder, a plate thereon, plate clamps mounted on the cylinder, a periplierally movable segment for moving the plate clamps, a crank arm journalled in said cylinder, a. crank pin on said crank arm engaging a slot in said segment, the said slot being tangent to the path ot travel of said crank pin when the latter is at the limitot its throw in the direction to bring the said plate clamps into clamping engagement with the said plate.

. he combination ot' a plate holding cylinder having longitudinally movablev plate clamps, a peripherally movable segment arranged to move the plate clamps longitudinally in either direction, a slot or recess in the segment engaged by a crank arm and means for moving said crank arm comprising a removable hand operated wrench actuated through a portion of a revolution only.

8. The combination otaplate holding cylinder having longitudinally movable plate clamps, means for moving said plate clamps, said means including` a crank arm movable through a portion of a revolution only, a squared place upon said crank arm, a wrench engaging said squared place, a flange on said crank arm to confine said wrench to said squared portion, a projection on the side of said wrench, radial channels or grooves corresponding ywith the limits of throw of the eranl; arm, arranged to admit the wrench to the crank arm when the latter is at either limit of its throw and an annular groove to permit the crank arm to be turned between the limits ot its throw when the wrench is in operative position on the crank 9. The combination of apla-te holding cylinder having longitudinally movable plate clam 3s, means tor moving said plate clamps, including a cranlt arm adapted to receive a wrench in one longitudinal position only, and elements on said wrench registering with elements on said cylinder to permit the operative engagement of said wrench with said cranlt arm at either end ot its throw and to retain said vrencli upon said crank arm at intermediate positions between the ends of its throw.

l0. llhe combination of a plate holding cylinr er having longitudinally movable plate clanips means for moving said plate clamps, including a crank arm actuated by a wrench through a portion only ot a ievolutioii and stop pins to limit the throw of the crank arm.

l1. rThe combination in a printing press ol a plate holding cylinder having longie tudinally movable plate clamps, means for moving the clamps including` a wrench, movable through a portion of a revolution to lock or unlock the plate on the cylinder, and stops for causing the wrench when moved to locking position to extend sidewise oli the cylinder and block access therefrom.

l2. The combination in a printing press of a plate holding cylinder having longitudinally movable plate clamps, means for moving the clamps including a wrench, niovable througli a portion of a revolution to lock or unlock the plate on the cylinder, and stops for either position of the wrench, said stops causing the wrench to extend above the cylinder and out oit the way when in unlocked position or sidewise olf the cylinder when in locked position so as to bai' access therefrom.

13. The combination in a plate holding cylinder having longitudinally in vable plate clamps, of a cam plate for moving the clamps, a plate spring between the cani plate and the clamps, and cam operating means 'for actuating` the cani plate.

14e. The combination with a plate cylinder and plate clamps slidingly mounted thereon and movable longitudinally thereof, ot blocks also mounted thereon and movable longitudinally thereof, right and left hand screw connections between said plate cla-inps and said blocks and means tor moving said blocks.

l5. The combination ot' a plate cylinder, a printing plate thereon, a plurality ot longitudinal grooves for each plate, a plate holding clamp in each groove, a sliding block at the outer end ot each groove, a right and left hand screw connection between each plate clamp and its corresponding` sliding block and means for moving said blocks sie multaneously, longitudinally in said grooves comprising a peripherally movable curved segment. having diagonal cani grooves formed in it, one for each sliding block, a roller on each block tor engaging both v. ot the diagonal groove and means ,tor i ing the segment peripherally in both direcn tions to eil'ect a longitudinal movement et the sliding blocks in either dir ction.

16. The coinbii ation in a plate holding cylinder having a longitudinally movable plate clamp and means for moving it to clanip the outer margin o an outer or end plate on said cylinder, ot a freely movable intermediate plate clainp to clamp the outer margin or an inner or middle plate on said cylinder, and means for operating said intermediate plate clamp comprising rods screw-threaded through one of said plate clamps and extending to engage the other ot said plate clamps.

17. The combination in a plate holding cylinder having longitudinally movable plate clamps, ot clamp blocks, a cam plate tor moving the clamps, a plate spring between tlie cam plate and the blochs, and cani operated means for actuating` the Cain plate.

18. The combination in a plate cylinder, of outer and inner sliding Clamps for clamping outer and inner platee on the cylinder, means for movingthe outer clamp longitudinally away from the outer plate and connections from said moving means engagging the inner face of the inner clamp for positively moving the inner clamp longitudinally away from the inner plate.

19. The combination in a plate holding cylinder having` longitudinally movable plate clamps7 of a cam plate for moving the clamps and cam operated means for aotuating the cam plate.

20. The combination in a plate holding cylinder having longitudinally movable plate clamps, of a cam plate for moving the clamps, a yielding resistance between the cam plate and the Clamps, and Cam operated means` for actuating the cam plate.

In testimony whereofa I have hereunto set my hand.

BRUCE CLARK WHTE. 

